The Caves of Cabarete.  The caves are part of El Choco National Park (protected area). The Cabarete Caves company offers short tours every day for RD$850 (or USD$20) per person.   Ask for information at the Cabarete Cave's office at the end of the Callejon de la Loma (street right in front of Ocean Dreams Plaza and Condominiums, west side of Cabarete Bay).   Lots of photos in Flickr!  Reviews of Caves of Cabarete.  

The Islabon Jungle River Tour.   About 3 miles east of Cabarete, the Jungle River Tour is a 2.5 hour-long eco-tour in the Islabon River (offered by Islabon River Tours (809-667-1660).  Includes visit to a mini-zoo housing local species (nice for children).  Cost:  USD$15 per person, children 5 and under free.  

Taino Farms Lazy River Float and Permaculture Farm Tour.
Taino Farms is an organic permaculture farm located in Los Brazos, 15mins inland from Sabaneta. The tour includes an hour long tour of an educational permaculture site, which includes food forests, aqupoincs, apiculture, rare tropical fruit trees, aquaculture and agrotourism. The tour is followed by an hour long float down the Rio Yasica, which is very relaxing and allows you to see local flora and fauna.  Sip on some beers and cool off while floating down the river. Finish the tour with a farm fresh lunch, prepared especially for your group, with the produce that was picked that day.  

Kaiceitos Circus.  Complete circus training facility located on Kite Beach inside Extreme Hotel. Instruction on Flying Trapeze every day except Sundays.  Professional staff teach all skill levels age and ability to fly through the air with the greatest of ease.  Reviews and more information on Tripadivsor Kaiceitos Circus